She was a family friend who lived in Chicago. I was moving there from my tiny hometown. On a snot-freezing day in January, my friend took time off from work to help me find an apartment I could afford—in a neighborhood with sidewalks that weren’t cordoned off with yellow crime-scene tape. Not an easy task, considering my secretary’s salary.

Being a self-absorbed twentysomething at the time, I didn’t even recognize—much less acknowledge—this act of kindness.

Until 20 years later. By then, I couldn’t find out where she was to thank her.

Then came Facebook.

But what if seeking her out after all these years made her think I was crazy? I was older and wiser now, so I refused to let my insecurities talk me out of expressing my gratitude. And by doing so, I learned that it’s never too late to say, “Thank you.”

Do you have a long-overdue thank-you? Gratitude has no expiration date. Here are a few simple rules to get you started.

Be personal
You can’t beat expressing gratitude with a pen and paper. It tells the person you’re thanking that he or she is important enough for you to take a little time and use words that aren’t crazy abbreviations typed with your thumbs while you’re watching TV.

Be honest
The best way to begin is to acknowledge that yes, you’re kinda late with the appreciation. Try something like: “I know it’s been a long time,” or “This may seem out of the blue.”

Be specific
There’s a chance the person you’re thanking has forgotten about what it is you’re so grateful for. What’s important is that you haven’t. Describe briefly what he or she did for you and what it meant.

Be sincere
You don’t have to write an essay. Your “thank you” can be short. It just needs to be, to be from the heart and to make an impact on the person you’re thanking. How you do that is up to you.